I want to filter out some rows with one of DataFrame's column which data is in a list.

df[df['column'].isin(mylist)]

But I found that it's case sensitive. Is there any method using ".isin()" with case insensitive?

One way would be by comparing the lower or upper case of the Series with the same for the list

df[df['column'].str.lower().isin([x.lower() for x in mylist])]

The advantage here is that we are not saving any changes to the original df or the list making the operation more efficient

Consider this dummy df:

    Color   Val
0   Green   1
1   Green   1
2   Red     2
3   Red     2
4   Blue    3
5   Blue    3

For the list l:

l = ['green', 'BLUE']

You can use isin()

df[df['Color'].str.lower().isin([x.lower() for x in l])]

You get

    Color   Val
0   Green   1
1   Green   1
4   Blue    3
5   Blue    3